1. Field of the Invention
The present invention relates generally to wireless communications, and more particularly, to a method and apparatus for forming a Wi-Fi P2P group using Wi-Fi Direct.
2. Description of the Related Art
Mobile terminals, which have evolved into smart phones, provide a variety of useful features to users through applications, are downloaded over wireless networks that expand the operational functionality of the basic mobile terminal. Among various features provided by mobile terminals, is a technology, referred to as Wi-Fi Direct that has been proposed by the Wi-Fi Alliance.
Wi-Fi Direct, a new communication method proposed by the Wi-Fi Alliance provides a feature in which devices supporting Wi-Fi Direct may share information by communicating with each other without hotspots, routers and/or Access Points (APs). Common electronic devices having undergone certification of Wi-Fi Direct, such as mobile terminals, printers, monitors, TVs, and game consoles, may perform wireless communication with each other using the Wi-Fi Direct technology.
Although Wi-Fi Direct is partially similar to Bluetooth in terms of inter-device wireless communication capability, Wi-Fi Direct is advantageous over Bluetooth in terms of the coverage and data rate. So, the Wi-Fi Direct feature may replace Bluetooth as the standard inter-device wireless communication technology. For example, while Bluetooth 4.0, the latest Bluetooth standard, supports coverage of a maximum of 100 m and a data rate of a maximum of 24 Mbps, Wi-Fi Direct supports coverage of a maximum of 200 m and a data rate of a maximum of 300 Mbps. Therefore, Wi-Fi Direct has the advantage over Bluetooth in many aspects.
Wi-Fi Direct, also called Wi-Fi P2P, supports a feature of forming a Wi-Fi P2P network by forming a Peer-to-Peer group (P2P group) among devices. The P2P group is then referred to as a Wi-Fi P2P group and includes a Group Owner (GO) and Group Clients (GCs).
A Group Owner, playing a role similar to the conventional wireless router, plays a central role in the Wi-Fi P2P group, and allows connection of other devices (e.g., GCs) or adjusts start and end of the P2P group.
A Group Owner may be seen as an AP from the viewpoint of Group Clients. Group Clients, which are the remaining devices, except for GO in the P2P group, operate as clients by being connected to the P2P group, and are provided with a communication feature with the Group Owner and other Group Clients in the P2P group.
In Wi-Fi Direct, intent values of respective devices are compared in order to form a Wi-Fi P2P group.
A device with the highest intent value becomes the Group Owner, and the other devices become Group Clients. Compared to Group Clients, the Group Owner consumes more power because it controls the overall operation of the Wi-Fi P2P group. Therefore, if a mobile terminal powered by a battery (hereinafter referred to as a “battery-powered mobile terminal”) operates as Group Owner in the Wi-Fi P2P group, it is highly likely to reduce a running time (or driving time) of the mobile terminal due to the rapid battery consumption.
However, when forming a Wi-Fi P2P group, the current Wi-Fi Direct determines Group Owner by simply comparing intent values without any other criteria, so the battery-powered mobile terminal is likely to be determined as Group Owner. For example, assuming that a battery-powered mobile terminal and TV powered by a constant power source, such as wall power (e.g., always-powered TV), form a Wi-Fi P2P group, the mobile terminal may be determined as a Group Owner, even though it would be desirable to have the TV be the Group Owner when the battery replacement issue is considered.
Therefore, there is a need for a method and apparatus capable of complementing the current Wi-Fi Direct feature of selecting Group Owners by considering additional criteria for determining a Group Owner in a P2P network.